feat: add cwd option to es6+ instrument command

index.js

@@ -193,15 +193,15 @@ NYC.prototype.addAllFiles = function () {
 NYC.prototype.instrumentAllFiles = function (input, output, cb) {
   let inputDir = '.' + path.sep
   const visitor = filename => {
-    const inFile = path.resolve(inputDir, filename)
+    const inFile = path.resolve(this.cwd, inputDir, filename)
     const inCode = fs.readFileSync(inFile, 'utf-8')
 
     const extname = path.extname(filename).toLowerCase()
     const transform = this.transforms[extname] || (code => code)
     const outCode = transform(inCode, { filename: inFile })
 
     if (output) {
-      const outFile = path.resolve(output, filename)
+      const outFile = path.resolve(this.cwd, output, filename)
       mkdirp.sync(path.dirname(outFile))
       fs.writeFileSync(outFile, outCode, 'utf-8')
     } else {
@@ -212,10 +212,11 @@ NYC.prototype.instrumentAllFiles = function (input, output, cb) {
   this._loadAdditionalModules()
 
   try {
-    const stats = fs.lstatSync(input)
+    const inputPath = path.resolve(this.cwd, input)
+    const stats = fs.lstatSync(inputPath)
     if (stats.isDirectory()) {
-      inputDir = input
-      this.walkAllFiles(input, visitor)
+      inputDir = inputPath
+      this.walkAllFiles(inputPath, visitor)
     } else {
       visitor(input)
     }

lib/commands/instrument.js

@@ -7,6 +7,7 @@ exports.command = 'instrument <input> [output]'
 exports.describe = 'instruments a file or a directory tree and writes the instrumented code to the desired output location'
 
 exports.builder = function (yargs) {
+  const cwd = process.cwd()
   return yargs
     .option('require', {
       alias: 'i',
@@ -28,6 +29,10 @@ exports.builder = function (yargs) {
       type: 'boolean',
       description: "should nyc's instrumenter produce source maps?"
     })
+    .option('cwd', {
+      describe: 'working directory used when resolving paths',
+      default: cwd
+    })
     .option('compact', {
       default: true,
       type: 'boolean',
@@ -73,6 +78,7 @@ exports.handler = function (argv) {
     produceSourceMap: argv.produceSourceMap,
     extension: argv.extension,
     require: argv.require,
+    cwd: argv.cwd,
     compact: argv.compact,
     preserveComments: argv.preserveComments,
     esModules: argv.esModules,

test/nyc-integration.js

@@ -606,6 +606,42 @@ describe('the nyc cli', function () {
         })
       })
 
+      it('works with a different working directory', function (done) {
+        const subdir = path.resolve(fixturesCLI, 'subdir')
+        const args = [bin, 'instrument', '--cwd', subdir, './input-dir', './output-dir']
+
+        const proc = spawn(process.execPath, args, {
+          cwd: fixturesCLI,
+          env: env
+        })
+
+        proc.on('exit', code => {
+          code.should.equal(0)
+          const target = path.resolve(subdir, 'output-dir', 'index.js')
+          fs.readFileSync(target, 'utf8')
+            .should.match(/console.log\('Hello, World!'\)/)
+          done()
+        })
+      })
+
+      it('works with a deep folder structure working directory', function (done) {
+        const subdir = path.resolve(fixturesCLI, 'subdir')
+        const args = [bin, 'instrument', '--cwd', subdir, '.', './output-dir']
+
+        const proc = spawn(process.execPath, args, {
+          cwd: fixturesCLI,
+          env: env
+        })
+
+        proc.on('exit', code => {
+          code.should.equal(0)
+          const target = path.resolve(subdir, 'output-dir', 'input-dir', 'index.js')
+          fs.readFileSync(target, 'utf8')
+            .should.match(/console.log\('Hello, World!'\)/)
+          done()
+        })
+      })
+
       it('can be configured to exit on error', function (done) {
         var args = [
           bin,